feat: add node info api

[magicalne]

Node info API will return godwoken version and backend configs.

$ curl http://localhost:8119 -X POST -H "Content-Type: application/json" -d '{"jsonrpc": "2.0", "method":"gw_get_node_info", "params": [], "id": 1}' 

The response looks like:

{
  "jsonrpc": "2.0",
  "result": {
    "version": "0.6.4 145deca",
    "backends": [
      {
        "validator_code_hash": "0x8b00c1699f34524ddd5fe27c92a696fb63160ec63fafbbecd003cd659d88642e",
        "generator_code_hash": "0xef5effea165330db9bf6cee52fb8c42c44479e3a5e0c9d3972eb84e948734382",
        "validator_script_type_hash": "0xa16fc0d4cc190f560090f1a195113808b0128d2c2c4e7a7331e384b5b3f23d9d"
      },
      {
        "validator_code_hash": "0x5f29228f6b53741b6ba42a90fc18b32228fcbd74ee2cdc7f1cb6bad3b0a27f93",
        "generator_code_hash": "0xcbb3ea2f404cede64b72b6e3a1b4826aa04cefaf18f790e9d009ce0c604eeec7",
        "validator_script_type_hash": "0xdf17edcdcfc2635639186895d71d0e453cb5cb510252fd7fbec1d25858666605"
      },
      {
        "validator_code_hash": "0xbe4da16f86f199c7a4b73e06be9732e384b528c7072abca7a00cfaa4551114d1",
        "generator_code_hash": "0x2822eb72c552e1f25219ba27866f831200aeaa6dbb6d89688ce69cb25f9eb443",
        "validator_script_type_hash": "0xccff2ab8be3e794edd03e2f310e34bff95f404bb3c971e2c2a3c8d5056047f8b"
      }
    ]
  },
  "id": 1
}